• Korean Journal of Poultry Science
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• v.36 no.3
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• pp.223-229
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• 2009

The objective of this study was to investigate the effect of the supplementation of antibiotics on meat quality grade of broiler carcasses under the Korean meat grading system. A total of 34,000 broiler carcasses, which were randomly selected 100 broilers from each farm in 340 broiler farms (305 farms with antibiotics; 35 farms without antibiotics), were used in this study. Average daily weight gain of broilers was not significantly affected by the use of antibiotics. The ratio of quality grade A was higher in the broiler carcasses from the farms with antibiotics supplementation (78.87%) than those without antibiotics (73.46%, P<0.05). The numbers of carcass defects, which are down-grade factors of meat grading system, were much higher in the broiler carcasses produced from the farms without antibiotics supplementation when compared with those with antibiotics. In particular, the incidence of the carcass defect on conformation was approximately 1.8 times higher in the carcasses from the farms without antibiotics supplementation than those with antibiotics, which showed the highest negative correlation with quality grade A. Therefore, the improvement of farm management system, the use of antibiotics alternatives from natural products, and a proper incentive should be considered in various ways to encourage farmers to reduce antibiotics usage in their farm and earn consumers' trust for antibiotics-free products.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.80-92
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• 2007

IPTV Services that is representative union service of broadcasting and telecommunication need guarantee of QoS, efficiency of multicasting, and hish bandwidth on the network. Because typical TDM based metro transport network was designed by transporting fixed voice traffic with stable and recovering method, it has a defect of bottleneck and a waste of bandwidth for acceptance of data traffic with burst feature and then all of data are treated equally at the transport network because it cannot classify between advanced high end service and best effort low end service. for completely resolving this kind of problem about increasing burst traffic and QoS issues, firstly we need to new design for transport network. This paper presents transformation method from TDM based metro transport network to packet based transport network and advantage and effectiveness of packet based transport network and also indicates technical factor and characters about method of packet transport system. As a result of research, the Packet Transport System, which is a transmission network for packet delivery, take in not only a specific character of legacy TDM but QoS, Multicast and high bandwidth, then, it is able to keep an effective bandwidth and a stabilized performance of packet transmissions. Additionally, if a fault be occurred on an optical link, the system is able to guarantee a differential QoS by an each service class using an algorithm to make certain of a traffic existence and contain a protective mechanism.

• Composites Research
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• v.12 no.3
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• pp.84-90
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• 1999

High alumina cement(HAC) and polyvinyl alcohol(PVA) based macro-defect-free(MDF) cement composites were reinforced using short carbon fibers, 3mm in length, 1-4% in weight fraction and insoluble polymers such as polyurethane, epoxy, phenol resin, in order to increase mechanical properties and water stability. The specimens were manufactured by the low heat-press(warmpress) method. In addition, the interface and the cross-linking reaction of cement and polymers was also studied by the SEM and TEM. Flexural strength of HAC/PVA based MDF cementitious composites was proportionally decreased with increasing fiber contents due to the undensified structure around fibers. The flexural strength of insoluble polymer added specimen was decreased with increasing fiber contents, while water stability was dramatically improved. Epoxy resin added specimen showed the highest strength with increasing fiber contents, compared with other specimens. The water stability of fiber content 4% added specimen immersed in water presented about 95%, 87% at 3 and 7 days immersed in water, respectively. The interfacial adhesive strength of fiber-matrix was very much improved due to cross linking reaction of polymer and metal ions of cement. Tensile strength of insoluble polymers added composites as linearly increased with increasing the fiber contents. The epoxy resin added specimen also showed highest tensile strength. The 4% fiber added specimen presented 30~80% higher strength than controlled specimen.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.154-161
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• 1997

Purpose: Traumatic rupture of the diaphragm is not easy to diagnose and often delayed. Delayed diagnosis of diaphragmatic rupture accompanied by higher chances of strangulation of herniated viscera which may result in higher morbility and mortality. The purpose of this study was to evaluate diagnostic accuracy of spiral CT, MRI and US for the diagnosis of diaphragmatic rupture in an animal model. Materials and Methods: Small, medium, and large sized transabdominal diaphragmatic ruptures were surgically made in experimental rabbits and then followed up with spiral CT, MR!, and US at 1 day, 3 day, and 1 week after operation. Results: US was superior to MR! or spiral CT in diagnosis of diaphragmatic rupture(P(0.05). The sensitivity and specificity were 94.4% and 92.9% for US, 54.0% and 85.7% for MRI, and 46.0% and 78.6% for spiral CT, respectively. The size of laceration was not related to diagnostic sensitivity in US. Sensitivity of MRI and spiral CT increased as the size of laceration were larger, but no statistical significance was present(P>0.05). All experimental animals developed pleural effusion or hemothorax one day after operation. In acute phase, US and MRI were more sensitive than spiral CT in detecting diaphragmatic rupture. Spiral CT was more sensitive than US and MRI in delayed phase but without statistical significance(P>0.05). In the experimental rabbits with accompanying visceral hernia through the diaphragmatic defect, diagnostic accuracy was found equally high among three image modalities(P>0.05). Conclusion: This study indicates that US is the most accurate diagnostic method in detecting injury to the diaphragm in a rabbit model. The findings obtained in this experimental study can be applied to the diaphragmatic rupture of human being.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.80-84
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• 2011

Empyema necessitatis refers to empyema that extends into the extrapleural space through a defect in the pleural surface. Tuberculous empyema necessitatis is a rare complication of tuberculosis. We experienced a 21-month-old boy with tuberculous empyema necessitatis with osteomyelitis in the right $7^{th}$ rib. He presented with a mass on the right lateral chest wall, which was soft and nontender, enlarging for one month. He also had mild fever. The plain radiograph of his chest revealed soft tissue swelling and calcified lymph node on the left axilla, and his PPD skin test was positive. CT scan of the chest showed empyema necessitatis at the right lower chest and upper abdominal walls with osteomyelitis of the right $7^{th}$ rib. He did not have concurrent pulmonary tuberculosis. Surgery was performed for diagnosis and treatment. In histopathologic findings, chronic granulomatous inflammation with caseation necrosis was shown and was positive for acid fast bacilli stain. In addition, M. tuberculosis complex was found as etiology by polymerase chain reaction. The patient has been treated with anti-tuberculous medication without any specific complication.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.153-160
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• 2009

Purpose : The intestinal mucosal defect has been known as one of the pathogenicmechanisms of IgA nephropathy. Oral antigens usually induce the activation of Th2 cells and mast cells. These cells secrete cytokines IL-4, IL-5 and TGF-$\beta$, which increase IgA production. Although ketotifen (benzocycloheptathiophene) is an H1 antagonist and a mast cell membrane stabilizer, it could protect the gastrointestinal membrane through inhibiting the production of IL-4, IL-5, PGE2, and LTB4, and decreasing the activity of nitric oxide synthease. Therefore, we have investigated if ketotifen may protect the development of IgA nephropathy with an oral antigen. Methods : ICR mice were used as an animal model orally with Poliovax only [ketotifen (-)], the other group was given oral ketotifen [ketotifen (+)] in addition to Poliovax. Results : Mesangial IgA deposition developed in 11 out of the 18 mice in the ketotifen (-) group, while in three out of the nine mice in ketotifen (+) group. The mesangial change developed in 16 out of the 18 mice in the ketotifen (-) group, while in five out of the nine mice in the ketotifen (+) group. Serum IL-4 and IL-5 levels were not significantly lower in the latter group than in the former. Conclusion : According to the statistical results from the above, ketotifen therapy would be beneficial to reducing mesangial changes in IgA nephropathy.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.105.2-105.2
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• 2011

화비정질 실리콘의 빛에 의한 노화현상 (light-induced degradation; LID)은 이미 1977년 보고된 Staebler-Wronski 효과에 의해서 확인된 바 있다. 이는 비정질 실리콘이 빛에 노출될 때, 이미 포함되어 있는 수소원자가 빛 에너지에 의해서 이동하게 되고, 이로 인해서 생성 또는 소멸되는 댕글링 본드 때문에 일어난다. 특히, 일상적인 태양광의 노출 하에서 태양전지의 장시간 성능을 예측하는데 물리적인 이해의 부족 및 기술 환경적인 어려움이 있고, 이러한 요인들은 안정된 태양전지를 개발하는데 장해요인으로 나타난다. 그러므로 비정질 실리콘 태양전지가 장시간 태양광에 노출되어 시간이 지남에 따라서 "성능이 어떻게 변하는지?" 그리고 "이에 대한 원인은 무엇인지?" 등은 여전히 과학적으로 풀어야할 숙제로 남아있다. 본 논문에서는 비정질 실리콘으로 구성된 태양전지가 태양광에 노출될 때 시간이 지남에 따라서 (1) 성능이 어떻게 변하는지, (2) LID의 변화는 언제 안정화되는지, 그리고 (3) 성능변화에 대한 원인은 무엇인지에 대해서 논의한다. 본 논문은 장시간 빛에 노출되는 비정질 실리콘 태양전지의 성능예측에 관해서 연구하였다. 결함밀도의 운동학적 모형을 통해서 태양광 노출에 대한 태양전지 성능변화를 예측하는데 초점을 맞추었고, 이를 위해서 태양전지에 조사되는 태양광 세기, 주변온도, 등이 고려되었다. 특히, 전하운반자의 수명이 결함밀도에 의해서 결정되기 때문에 비정질 실리콘 태양전지의 빛에 대한 노화현상 (LID)이 확장지수함수 (stretched-exponential) 완화법칙을 따르는 결함밀도에 의해서 물리적으로 설명된다. 한편 이와 같은 물리적 계산의 유용성을 확인하기 위해서 동일한 태양전지에 대해서 AMPS-1D 컴퓨터 프로그램을 사용하였고, 이를 통해서 비정질 실리콘 태양전지의 빛에 대한 노화현상을 물리적 및 정량적으로 이해하였다. 본 연구에 적용되는 태양전지는 비정질 실리콘으로 구성된 pin 구조 (glass/$SnO_2$/a-SiC:H:B/a-Si:H/a-Si:H:P/ITO)로서 다음과 같은 특성을 갖는다: 에너지 띠간격~1.72 eV, 두께~400 nm, 내부전위~1.05 V, 초기 fill factor~0.71, 초기 단락전류~16.4 mA/$cm^2$, 초기 개방전압 0.90 V, 초기 변환효율 10.6 %. 우리는 이와 같은 연구를 통해서 과학적으로 비정질 실리콘의 빛에 의한 노화현상을 이해하고, 기술적으로 효율 및 경제성이 높은 태양전지의 개발에 도전한다.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.521-526
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• 2008

Purpose: Most burn scar contractures are curable with skin grafts, but free flaps may be needed in some cases. Due to the adjacent tissue scarring, local flap is rarely used, and thus we may consider free flap which gives us more options than local flap. However, inappropriate performance of free flap may lead to unsatisfactory results despite technical complexity and enormous amount of effort. The author will discuss the points we should consider when using free flaps in treating burn scar contractures Methods: We surveyed patients who underwent free flaps to correct burn scar contractures from 2000 to 2007. We divided patients into two groups. The first group was those in which free flaps were inevitable due to exposure of deep structures such as bones and tendons. The second group was those in which free flap was used to minimize scar contracture and to achieve aesthetic result. Results: We performed 44 free flap on 42 patients. All of the flaps were taken well except one case of partial necrosis and wound dehiscence. Forearm free flap was the most common with 21 cases. Most of the cases(28 cases) in which free flaps were inevitable were on the wrist and lower limbs. These were cases of soft tissue defect due to wide and extensive burns. Free flaps were done in 16 cases to minimize scar contracture and to obtain aesthetic outcome, recipient sites were mostly face and upper extremities. Conclusion: When using free flaps for correction of burn scar contractures, proper release and full resurfacing of the contracture should be carried out in advance. If inadequate free flap is performed, secondary correction is more challenging than in skin grafts. In order to optimize the result of reconstruction, flap thickness, size and scar of the recipient site should be considered, then we can achieve natural shape, and minimize additional correction.

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.118-123
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• 2012

Background : An area of the skull exposed by burn injury has been covered by various methods including local flap, skin graft, or free flap surgery. Each method has disadvantages, such as postoperative alopecia or donor site morbidities. Due to the risk of osteomyelitis in the injured skull during the expansion period, tissue expansion was excluded from primary reconstruction. However, successful primary reconstruction was possible in burned skull by tissue expansion. Methods : From January 2000 to 2011, tissue expansion surgery was performed on 10 patients who had sustained electrical burn injuries. In the 3 initial cases, removal of the injured part of the skull and a bone graft was performed. In the latter 7 cases, the injured skull tissue was preserved and covered with a scalp flap directly to obtain natural bone healing and bone remodeling. Results : The mean age of patients was $49.9{\pm}12.2$ years, with 8 male and 2 female. The size of the burn wound was an average of $119.6{\pm}36.7cm^2$. The mean expansion duration was $65.5{\pm}5.6$ days, and the inflation volume was an average of $615{\pm}197.6mL$. Mean defect size was $122.2{\pm}34.9cm^2$. The complications including infection, hematoma, and the exposure of the expander were observed in 4 cases. Nonetheless, only 1 case required revision. Conclusions : Successful coverage was performed by tissue expansion surgery in burned skull primarily and no secondary reconstruction was needed. Although the risks of osteomyelitis during the expansion period were present, constant coverage of the injured skull and active wound treatment helped successful primary reconstruction of burned skull by tissue expansion.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.499-503
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• 2004

Background: We investigated the longevity, thresholds of epicardial pacemaker and causes of reoperation in the pediatric patients who underwent epicardial pacemaker implantation performed during the last 13 years Material and Method: 121 operations were performed in 83 patients from January 1989 to July 2002. We analyzed the stimulation threshold, resistance, R-wave and P-wave, and sensitivity of pacemaker lead at initial implantation. Longevity and causes of reoperations were investigated. Result At implantation, epicardial ventricular mean stimula-tion threshold was 1.2$\pm$0.1 (0.1∼5) mV, mean resistance was 519.1$\pm$18.1 (319∼778) Ohm, and mean R-wave sensitivity was 8.9$\pm$0.7 (4∼20) mV, and mean P wave sensivity was 2.5$\pm$0.7 (0.4∼12) mV. The mean longe-vity of pacemaker generator was 64.7$\pm$3.7 (2∼196) months. The reoperation free rate was 94.6% for 1 year, 93.6% for 2 years, 80.8% for 5years, 63.7% for 7 years, and 45.5% for 10 years. The causes of reoperation were battery waste in 26 cases and lead malfunction in 9 cases. There was no postoperative death related to pacemaker malfunction. Conclusion: in the childrens, average longevity of epicardial pacemaker was within accep-table range. 19.1% of the patients required pacemaker related reoperation. However, recent developments, including steroid eluting lead, 6.7% of the patients required pacemaker related reoperation, look promising in expansion of pacemaker life span.